Skip to content

MS-DOS

DOS games run via the dosbox-pure core (part of EmulatorJS). Create a DOS platform (folder named dos) and drop your games in. Operator tuning lives in Configuration File → emulatorjs (notably disable_batch_bootup for DOS-specific issues).

Upload games as .zip

dosbox-pure knows how to unzip and auto-mount zipped DOS games, which is much easier than packaging a raw folder.

Save states work

Once you've got a game running, save state and resume from there, so you only need to do the boot dance once per game.

Running games

DOS games come in three flavours, each needing a different approach:

  • Homebrew: indie/modern DOS games, just an .exe that usually Just Works once mounted.
  • Shareware demos: what most "free DOS games" sites distribute, same as homebrew with all files in one folder.
  • Retail: need the original CD mounted alongside the installed game files. More work, and every game is different.

The basic flow inside dosbox-pure: select Commandline from the initial loading screen, then:

mount A/-t floppy     # mount the game files
A:                      # switch to that drive
dir                     # find the .EXE
filename.exe            # launch

Works for homebrew and shareware, but retail games usually fail here because they want a CD mounted somewhere.

Auto-config with .conf files

Not for the faint of heart

Building working .conf files is trial-and-error, so plan for it.

dosbox-pure looks for a .conf file matching the .exe name before booting. If found, it reads the config, mounts whatever's specified, and runs the [autoexec] block. Once you have a working .conf, click Play → game boots straight into DOS → [autoexec] runs → you're in the game, no typing.

DOOM shareware example

  1. Confirm no .ins, .cue, or .bin files in the folder (those mean it's a retail CD game).
  2. Create DOOM.conf next to DOOM.exe:
DOOM.conf 
[sdl]
fullscreen=TRUE
fulldouble=false
fullresolution=Fixed
windowresolution=1280x800
output=direct3d
autolock=true
sensitivity=100
waitonerror=true
priority=higher,normal
mapperfile=mapper-0.74.map
usescancodes=true

[dosbox]
machine=svga_s3
captures=.\Captures\
memsize=16

[render]
frameskip=0
aspect=false
scaler=normal3x

[cpu]
core=auto
cputype=auto
cycles=max
cycleup=10
cycledown=20

[mixer]
nosound=false
rate=22050
blocksize=2048
prebuffer=10

[midi]
mpu401=intelligent
mididevice=default
midiconfig=

[sblaster]
sbtype=sb16
sbbase=220
irq=7
dma=1
hdma=5
sbmixer=true
oplmode=auto
oplemu=default
oplrate=44100

[gus]
gus=false
gusrate=44100
gusbase=240
gusirq=5
gusdma=3
ultradir=C:\ULTRASND

[speaker]
pcspeaker=true
pcrate=44100
tandy=auto
tandyrate=44100
disney=true

[joystick]
joysticktype=fcs
timed=true
autofire=false
swap34=false
buttonwrap=false

[serial]
serial1=dummy
serial2=dummy
serial3=disabled
serial4=disabled

[dos]
xms=true
ems=true
umb=true
keyboardlayout=auto

[ipx]
ipx=false

[autoexec]
@echo off
Mount C ".."
C:
cls
DOOM.exe
:exit
exit

The [autoexec] block does the work: mount the current folder as C:, switch to it, clear the screen, run DOOM.exe, then drop back to the prompt on quit.

  1. Zip up the folder (including DOOM.conf).
  2. Upload under the dos platform.
  3. Click Play, and the game boots.

A blank screen after boot usually points at a path or mount issue in [autoexec] (see Troubleshooting below).

Retail games with CDs

Retail games need the game CD image mounted alongside the install directory.

GOG DOS re-releases don't work

GOG's DOS games ship with custom wrappers (DOSBox Staging, ScummVM scripts, etc.) that don't translate to dosbox-pure, with a 100% failure rate observed. For GOG titles, extract the underlying game files and build a .conf yourself.

Dungeon Keeper Gold example

  1. Organise files:
DungeonKeeper/
    KEEPER.exe
    KEEPER.cfg
    ...
    CD/
    DUNGEON.CUE
    DUNGEON.BIN
  1. Read KEEPER.cfg, which tells you where the game expects the CD.
  2. Create KEEPER.conf matching the .exe name:
KEEPER.conf 
[sdl]
fullscreen=TRUE
fulldouble=false
fullresolution=Fixed
windowresolution=1280x800
output=direct3d
autolock=true
sensitivity=100
waitonerror=true
priority=higher,normal
mapperfile=mapper-0.74.map
usescancodes=true

[dosbox]
machine=svga_s3
captures=.\Captures\
memsize=16

[render]
frameskip=0
aspect=false
scaler=normal3x

[cpu]
core=auto
cputype=auto
cycles=max
cycleup=10
cycledown=20

[mixer]
nosound=false
rate=22050
blocksize=2048
prebuffer=10

[midi]
mpu401=intelligent
mididevice=default
midiconfig=

[sblaster]
sbtype=sb16
sbbase=220
irq=7
dma=1
hdma=5
sbmixer=true
oplmode=auto
oplemu=default
oplrate=44100

[gus]
gus=false
gusrate=44100
gusbase=240
gusirq=5
gusdma=3
ultradir=C:\ULTRASND

[speaker]
pcspeaker=true
pcrate=44100
tandy=auto
tandyrate=44100
disney=true

[joystick]
joysticktype=fcs
timed=true
autofire=false
swap34=false
buttonwrap=false

[serial]
serial1=dummy
serial2=dummy
serial3=disabled
serial4=disabled

[dos]
xms=true
ems=true
umb=true
keyboardlayout=auto

[ipx]
ipx=false

[autoexec]
@echo off
Mount C ".."
C:
cd CD
imgmount d DUNGEO~8.CUE -t iso -fs iso
cd ..
cls
KEEPER.exe
:exit
exit

Key [autoexec] lines for retail:

  • Mount C "..": game files as C:.
  • imgmount d DUNGEO~8.CUE -t iso -fs iso: CD image as D:.
  • cd ..: back to C:\ where KEEPER.exe lives.
  • KEEPER.exe: run.

(File names in DOS are 8.3, so DUNGEON8.CUE becomes DUNGEO~8.CUE.)

  1. Zip, upload, play.

Troubleshooting

If a game lands on a blank DOS prompt or won't boot:

  1. Strip the [autoexec] .exe line so dosbox-pure drops you at a prompt after mounting. Then check manually:
    • Is the game directory mounted correctly?
    • type DEFAULT.cfg (or whatever the game's config is named): the install path should match what you mounted.
  2. Check drive paths. Many retail DOS games hard-code D:\ as the CD. If you mount the CD as E: the game won't find it.
  3. Debug with native dosbox-pure. Run the same zip in RetroArch with the dosbox-pure core. If it works there it should work, and if not, the .conf is the problem.

Full option reference available at dosbox-pure wiki.